N, C, and H Isotopes of Isolated or Dissolved Gases Gaseous samples are injected into a Thermo GC IsoLink for chromatographic separation and combustion (N and C) or pyrolysis (H), then introduced via ConFlo IV into a Thermo MAT 253 for measurement. See the gas sample submission page for sample submission details. H, O, N, C, and S Isotopes of Pure Gases in Glass Break Seals Break seals are loaded and the inlet system is pumped out under high vacuum. The break seal is snapped, and sample gas is introduced into the IRMS for measurement against a reference gas with a known isotopic value. QA/QC Long-term standard deviations of δ18O, δ15N, and δ13C measurements is better than 0.1 permil. Long-term standard deviation of δ34S measurements is better than 0.2 permil. Long-term standard deviations of δ2H measurements is better than 2 permil.
